LED pattern projector for 3D camera platforms

ABSTRACT

A light pattern projector with a pattern mask to spatially modulate an intensity of a wideband illumination source, such as an LED, and a projector lens to reimage the spatially modulated emission onto regions of a scene that is to be captured with an image sensor. The projector lens may comprise a microlens array (MLA) including a first lenslet to reimage the spatially modulated emission onto a first portion of a scene, and a second lenslet to reimage the spatially modulated emission onto a first portion of a scene. The MLA may have a fly&#39;s eye architecture with convex curvature over a diameter of the projector lens in addition to the lenslet curvature. The pattern mask may be an amplitude mask comprising a mask pattern of high and low amplitude transmittance regions. In the alternative, the pattern mask may be a phase mask, such as a refractive or diffractive mask.

BACKGROUND

A digital camera is a component often included in electronic mediadevice platforms. Digital cameras are now available in wearable formfactors (e.g., video capture earpieces, video capture headsets, videocapture eyeglasses, etc.), as well as embedded within smartphones,tablet computers, and notebook computers, etc. Digital cameras typicallyinclude image sensors with 2D arrays of photosensitive areas (e.g.,photodiodes) where light is collected and converted into charge(photocharge). The photocharge is a function of the amount of lightcollected, which is dependent on both the light intensity and theduration of collection. Photocharge is read out and correlated withspatial position within the array to construct a representative image ofa scene from which the light was collected.

Three-dimensional (3D) cameras are becoming more common, and can now befound on many devices or platforms. These devices provide enhancedentertainment and utility experiences to an end user. For example,photography may be enhanced by depth information output from the 3Dcamera. Depth information may be derived through one or more techniquesincluding stereo imaging, structured light, coded light, time of flight(TOF), and lidar. Deriving depth information in a manner that isdependent on features in the scene is challenging because suitablefeatures may not always be available. Technologies that address thischallenge are therefore advantageous.

BRIEF DESCRIPTION OF THE DRAWINGS

The material described herein is illustrated by way of example and notby way of limitation in the accompanying figures. For simplicity andclarity of illustration, elements illustrated in the figures are notnecessarily drawn to scale. For example, the dimensions of some elementsmay be exaggerated relative to other elements for clarity. Further,where considered appropriate, reference labels have been repeated amongthe figures to indicate corresponding or analogous elements. In thefigures:

FIG. 1 is a schematic illustrating operation of a camera platformincluding a LED pattern projector, in accordance with some embodiments;

FIG. 2 is a method of LED pattern projection and image capture, inaccordance with some embodiments;

FIG. 3A is a schematic of a LED pattern projector, in accordance withsome embodiments;

FIG. 3B is a schematic of a LED pattern projector, in accordance withsome embodiments;

FIG. 3C is a schematic of a LED pattern projector, in accordance withsome embodiments;

FIG. 4A is a plan view of a lenslet array that may be employed in a LEDpattern projector, in accordance with some embodiments;

FIG. 4B is a cross-sectional view of a flat lenslet array that may beemployed in a LED pattern projector, in accordance with someembodiments;

FIG. 4C is a cross-sectional view of a concave-convex lenslet array thatmay be employed in an LED pattern projector, in accordance with someembodiments;

FIG. 4D is a cross-sectional view of a bi-convex lenslet array that maybe employed in an LED pattern projector, in accordance with someembodiments;

FIG. 5A is a plan view of a lenslet array that may be employed in an LEDpattern projector, in accordance with some embodiments;

FIG. 5B is a cross-sectional view of a flat lenslet array that may beemployed in an LED pattern projector, in accordance with someembodiments;

FIG. 5C is a cross-sectional view of a plano-convex lenslet array thatmay be employed in an LED pattern projector, in accordance with someembodiments;

FIG. 5D is a cross-sectional view of a concave-convex lenslet array thatmay be employed in an LED pattern projector, in accordance with someembodiments;

FIGS. 6A, 6B, 6C, and 6D are cross-sectional views of masked lensletarrays that may be employed in LED pattern projectors, in accordancewith some embodiments;

FIGS. 7A and 7B are isometric views of a pattern projector including apattern mask and lenslet array, in accordance with some embodiments;

FIG. 7C is a schematic of LED pattern projection with a masked lensletarray, in accordance with some embodiments;

FIG. 8 is device platform including a camera and a LED patternprojector, in accordance with some embodiments;

FIG. 9 is a diagram of an exemplary system employing a camera a LEDpattern projector, in accordance with some embodiments; and

FIG. 10A is a diagram of an exemplary mobile handset platform includinga camera and a LED pattern projector, in accordance with someembodiments; and

FIG. 10B is a diagram of an exemplary quadcopter platform including acamera and a LED pattern projector, in accordance with some embodiments.

DETAILED DESCRIPTION

One or more embodiments or implementations are now described withreference to the enclosed figures. While specific configurations andarrangements are discussed, it should be understood that this is donefor illustrative purposes only. Persons skilled in the relevant art willrecognize that other configurations and arrangements may be employedwithout departing from the spirit and scope of the description. It willbe apparent to those skilled in the relevant art that techniques and/orarrangements described herein may also be employed in a variety of othersystems and applications other than what is described herein.

Reference is made in the following detailed description to theaccompanying drawings, which form a part hereof, wherein like numeralsmay designate like parts throughout to indicate corresponding oranalogous elements. It will be appreciated that for simplicity and/orclarity of illustration, elements illustrated in the figures have notnecessarily been drawn to scale. For example, the dimensions of some ofthe elements may be exaggerated relative to other elements for clarity.Further, it is to be understood that other embodiments may be utilizedand structural and/or logical changes may be made without departing fromthe scope of claimed subject matter. It should also be noted thatdirections and references, for example, up, down, top, bottom, over,under, and so on, may be used to facilitate the discussion of thedrawings and embodiments and are not intended to restrict theapplication of claimed subject matter. Therefore, the following detaileddescription is not to be taken in a limiting sense and the scope ofclaimed subject matter defined by the appended claims and theirequivalents.

In the following description, numerous details are set forth, however,it will be apparent to one skilled in the art, that the presentinvention may be practiced without these specific details. In someinstances, well-known methods and devices are shown in block diagramform, rather than in detail, to avoid obscuring the present invention.Reference throughout this specification to “an embodiment” or “in oneembodiment” means that a particular feature, structure, function, orcharacteristic described in connection with the embodiment is includedin at least one embodiment of the invention. Thus, the appearances ofthe phrase “in an embodiment” in various places throughout thisspecification are not necessarily referring to the same embodiment ofthe invention. Furthermore, the particular features, structures,functions, or characteristics may be combined in any suitable manner inone or more embodiments. For example, a first embodiment may be combinedwith a second embodiment anywhere the two embodiments are not specifiedto be mutually exclusive.

The terms “coupled” and “connected,” along with their derivatives, maybe used herein to describe structural relationships between components.It should be understood that these terms are not intended as synonymsfor each other. Rather, in particular embodiments, “connected” may beused to indicate that two or more elements are in direct physical orelectrical contact with each other. “Coupled” my be used to indicatedthat two or more elements are in either direct or indirect (with otherintervening elements between them) physical or electrical contact witheach other, and/or that the two or more elements co-operate or interactwith each other (e.g., as in a cause an effect relationship).

The terms “over,” “under,” “between,” “on”, and/or the like, as usedherein refer to a relative position of one material layer or componentwith respect to other layers or components. For example, one layerdisposed over or under another layer may be directly in contact with theother layer or may have one or more intervening layers. Moreover, onelayer disposed between two layers may be directly in contact with thetwo layers or may have one or more intervening layers. In contrast, afirst layer “on” a second layer is in direct contact with that secondlayer. Similarly, unless explicitly stated otherwise, one featuredisposed between two features may be in direct contact with the adjacentfeatures or may have one or more intervening features.

As used throughout this description, and in the claims, a list of itemsjoined by the term “at least one of” or “one or more of” can mean anycombination of the listed terms. For example, the phrase “at least oneof A, B or C” can mean A; B; C; A and B; A and C; B and C; or A, B andC.

As described further below, a camera platform with one or more imagesensor includes a light pattern projector operable to project a lightpattern upon a scene within a field of view (FOV) of the image sensor.The pattern projector may advantageously include a LED illuminationsource having any suitable wavelength(s). LED illumination sources areto be distinguished from laser illumination sources. Although lasersources can provide high contrast at low powers (i.e., high efficiency),laser-based pattern projection approaches can suffer from relativelyhigh cost, speckle artifacts, and eye safety concerns. Laser speckle isa particular problem for laser-based pattern projection approaches as itcan severely impact the RMS error of a 3D depth sensor (e.g., by >30%),even after various electronic or optical schemes are employed tominimize laser speckle. Drift is another drawback of laser-based patternprojection systems because laser intensity and/or wavelength may changeover time, for example, in response to temperature fluctuations.

In accordance with embodiments herein, a LED pattern projector employsone or more projection lenses, a LED source, and a pattern mask betweenthe LED source and projection lenses. FIG. 1 is a schematic illustratingcomponents and operation of a camera platform having LED patternprojector, in accordance with some embodiments. In FIG. 1, a cameraplatform 101 is operable to collect one or more image frame of a realworld scene 105. Within scene 105, depth is aligned with the z-axis.This is a simplification reasonable where camera FOV 116 is relativelysmall and complications associated with a larger FOV are omitted for thesake of brevity. Camera platform 101 includes first image sensor 115A, asecond image sensor 115B, and a light pattern projector 125.

In the illustrated embodiment, camera platform 101 may be considered anarray camera having a plurality of image sensors 115A, 115B with apredetermined baseline relationship. Image sensors 115A and 115B may beof any known digital sensor architecture such as, but not limited to, aCMOS sensor array. Image sensors 115A, 115B are advantageously operableto collect RGB (e.g., 400-700 nm wavelengths) as well as NIR (e.g.,701-1200 nm) within camera FOV 116. CMOS image sensors are inherentlyNIR sensitive to some extent and may therefore be considered RGB(NIR)sensors. For some embodiments, camera platform 101 includes an imagesensor and/or color filter configured to include a specific NIR channel,often referred to as RGBNIR sensor as opposed to an RGB(NIR) sensor thatdoes not have an independent NIR channel. Each image sensor may receivelight through one or more apertures. Separate RGB and NIR apertures maybe employed, for example. A filter array that passes both NIR and RGBwithin at least some portions of an image sensor array may be disposedwithin the camera optical path. In one exemplary embodiment, the filterarray is a Bayer color filter array (CFA). In other embodiments, thefilter array is a NIR-enhanced filter array (e.g., where half of greenfilter tiles of the Bayer mosaic are replaced with a visible lightblocker). Image sensors 115A, 115B may provide an intensity resolutionof 10 bits, or more per pixel, and may be operable to capture continuousvideo frames progressively. Image sensors 115A, 115B may have a pixelfrequency of 25 MHz, or more. Camera platform 101 may further include ananalog amplifier, an A/D converter, and other components to convertincident light into a digital signal corresponding to raw RGB and IRimage data.

Each of image sensors 115A, 115B are to output image data captured froma different camera viewpoint. In exemplary embodiments, the image fromeach viewpoint is captured over substantially the same time span suchthat the two resulting image frames contain image data for a singlescene 105. One of the image frames collected may be designated areference and combined with the other into a captured image frame 150having depth information. For example, where image sensor 115A has thesame or higher resolution (e.g., 8 megapixel, or more) as image sensor115B (e.g., 720p, HD, 8 megapixel, or more), image sensor 115A mayprovide a default reference image and image data from sensor 115B may beemployed to determine disparity (or other depth) information associatedwith captured image frame 150. Image sensors 115A, 115B are eachassociated with predetermined baseline vector (length and direction)characterizing their different viewpoints. In an exemplary embodimentwhere image sensors 115A, 115B are on a mobile platform, the baselinevector may have a length of millimeters to tens of centimeters,depending on the form factor. In other embodiments, where image sensors115A, 115B are separate infrastructure fixtures, baseline lengths may beon the order of meters. Additional image frames 151 having depthinformation may be collected over subsequent time intervals, for examplegenerating 3D video.

Although two image sensors are illustrated in FIG. 1, any number ofimage sensors may be included in an array camera as embodiments hereinare not limited in this respect. Alternative embodiments may also employonly a single image sensor. For single sensor embodiments, a baselinevector describing the relationship between the single image sensor(e.g., 115A) and light pattern projector 125 is employed to derive depthinformation. Projection LED source 130 may cast structured light, forexample, that is collected by the image sensor and processed by anyknown technique to determine depth information for image frame 150 basedon locations of discrete illumination points within a collected frame ofimage data and the known origin of the illumination points.

With multiple image sensors 115A and 115B, pattern projector 125 neednot cast structured light, and in some exemplary embodiments, patternprojector 125 casts a fixed pattern of light, such as a pseudo-randomlight pattern 120 comprising a plurality of points of illumination(e.g., in the IR band) projected into camera FOV 116. In this example,projector field of illumination 111 is larger than camera FOV 116, andlight pattern 120 may illuminate substantially all of camera FOV 116over a first time increment during which sensors 115A, 115B are samplinglight from scene 105. In some embodiments, a platform 101 includes aglobal shutter (not depicted) such that all pixels of a sensor array ineach of image sensors 115A and 115B actively sample the illuminatedscene concurrently. Other embodiments where platform 101 includes arolling shutter (not depicted) are also possible.

Upon collecting image frame 150, depth information may be computed basedat least in part on projected light pattern 120. For example, pixelcorrespondence may be deduced by determining disparity between discreteillumination points making up feature pattern 120. Such depthinformation may then be employed, for example, to assign segmentationlabels to various segments in the scene. In the example illustrated inFIG. 1, three segments (background 155, subject 160 and subject 165) areidentified from image frame 150 based, at least in part, on depthinformation determined from the feature pattern 120. The segmentationshown in FIG. 1 is, however, only one example of the type of depthprocessing enabled by light pattern 120.

Light pattern projector 125 includes a LED source 130. LED source 130 isgenerally an extended source, for example having a relatively wideemission angle (e.g., with lambertian radiation distribution having ahalf-emission cone angle of approximately 65°), and having a relativelywide emission spectrum (e.g., 4-20 nm). While the emission band may varywith implementation, in some examples LED source 130 emits within theNIR band (e.g., ˜850 nm). With larger etendue than a laser source, LEDsource 130 may be relatively more difficult to manipulate to create alight pattern comprising the many thousands (e.g., 20K-100K) ofillumination points advantageous for good depth processing. For a smallform factor and low power consumption, LED source 130 advantageouslyincludes far fewer emission elements (emitters) than illumination points(e.g., dots) projected onto scene 105, and a pattern mask 135 is reliedupon to spatially modulate an intensity of the light into a pattern withsuitable contrast. As described further below, pattern mask 135 maycomprise elements that modulate amplitude and/or phase of light emittedby LED source 130. Although LED source 130 may comprise more than oneemitter (e.g., an emitter array), in some exemplary embodiments LEDsource 130 includes only a single LED emitter that is to be powered atany given time to generate feature pattern 120. This is in contrast toan emitter array that might include an array of many emitters that areto be concurrently powered, each corresponding to an individualprojector element, or “proxel,” having some correspondence with one ormore illumination points in feature pattern 120. While such emitterarray implementations are possible, embodiments where pattern projector125 comprises a single emitter enable an advantageously small formfactor.

Light projector 125 further includes one or more projection lenses 140.Projection lenses 140 are to cast light modulated by pattern mask 135onto scene 105 over a sufficiently large projection FOV 111. Inexemplary embodiments, projection FOV 111 is at least 60°. As describedfurther below, projection lens 140 and pattern mask 135 may beimplemented as discrete optical elements, but may alternatively beintegrated together. When integrated together, light projector 125 mayhave an advantageously small form factor and/or well-controlledperformance.

FIG. 2 illustrates methods 201 of LED illuminated pattern projection insynchronization with image capture, in accordance with some exemplaryembodiments. Methods 201 may be performed with a camera platform thatincludes a LED projector capable of casting a plurality of point ofillumination upon a scene, such as one including LED pattern projector125, introduced above. Methods 201 begin at block 210 where a projectorin accordance with one or more embodiments is energized by any means(e.g., capacitor, battery, etc.). In exemplary embodiments, theprojector is to concurrently illuminate multiple portions of a scenewithin the image sensor FOV, and the projector may advantageouslyilluminate substantially the entire scene within the image sensor FOV.In some exemplary embodiments, the projected illumination is a fixedpattern. In some other embodiments, the illumination is a spatiallycoded pattern, or a temporally coded pattern (e.g., structured or codedlight projection). At block 210, a projector controller may initiate theillumination by driving a single LED source to emit light and illuminatethe entire scene corresponding to that to be concurrently capturedduring block 220.

At block 220, image data is read out from the image sensor, for exampleas consecutive lines (e.g., rows) of a sensor array. In one exemplaryembodiment, the image data includes pixel values (e.g., indicative oflight intensity) for each of a plurality of color channels. The colorchannels may be in any color space. In some embodiments, the image dataincludes color information in the RGB color space. In furtherembodiments, the image data includes an NIR channel. The image data maybe received into an image signal processor (ISP), for example.

Methods 201 continue at block 230 where the image data collected atblock 220 is processed to determine associated depth information. Insome embodiments, at least NIR data is processed to determine pixelcorrespondence between a plurality of image frames. In some examples,the depth information determined at block 230 is in the form of a depthmap correlated with the image pixels, each having an image coordinatex,y associated with the image frame. In other embodiments, the depthinformation determined at block 230 is in the form of a disparity mapcorrelated with the image pixels, each image pixel having an imagecoordinate x,y associated with the image frame. For some disparityembodiments, image data collected at block 220 may be accompanied by CMparameters, such as a camera focal length (C_(f)) and a camera baseline(C_(b)), from which disparity values for pixels in a first image (e.g.,collected by a first sensor at block 220) may be estimated based ontheir correspondence with pixels in a second image (e.g., collected by asecond sensor at block 220). Disparity estimation may be accomplishedthrough any known technique or algorithm, as embodiments herein are notlimited in this respect. As an alternative to determining disparitybetween two sensors, in some other embodiments where the origin of afeature in an illumination pattern is known (e.g., as with structuredlight) the disparity may be determined based on a known baseline betweenthe LED pattern projector and a single image sensor. Methods 201 thencomplete at block 240 where depth information is stored to memory inassociation with corresponding pixel data, according to any suitabletechniques.

FIG. 3A is a schematic of a LED pattern projector 301, in accordancewith some embodiments. LED pattern projector 301 may, for example, beemployed as LED pattern projector 125 (FIG. 1), introduced above. Infurther reference to FIG. 3A, projector 301 includes a compound lens340, comprising a plurality of simple lenses that may each be of anysuitable shape, made of any materials having refractive indices known tobe suitable for the purpose of collection and projection, and arrangedone after the other along a common optical axis 304. Notably, compoundlens 340 may be implemented as any number of discrete simple lenses orone or more monolithic compound lenses. In some exemplary embodiments,compound lens 340 includes at least one collector lens 341 proximal toLED source 130, and one projector lens 342 separated from LED source 130by the collector lens 341. Collector lens 341 is to collect andcollimate light emitted by LED source 130. Projector lens 342 is toproject an image plane of collector lens 341 upon a scene over desiredFOV (e.g., associated with an image capture device).

In the illustrated example, compound lens 340 comprises five lenses, butembodiments with two, three, four, or more than five lens, are alsopossible. The greater the number of lenses employed, the better theresolution of compound lens 340 at a given spatial frequency, and thehigher the spatial intensity contrast (i.e., a high optical transferfunction (OTF) and/or modulation transfer function (MTF)) a pattern mayhave for a given FOV. The number of optical elements employed incompound lens 340 may therefore depend, at least in part, on the FOVover which a pattern is to be projected. For example, to generate a highMTF pattern over a 70+° FOV, a compound lens 340 may require fourlenses. For a significantly smaller FOV (e.g., 50°), a single compoundoptical element (e.g., a molded acrylic element) may be employed as bothcollector lens 341 and projector lens 342. Cost and/or form factorconstraints of a mobile device, for example, may also limit compoundlens 340 to four, or fewer, optical elements.

As noted above, pattern mask 135 may be an amplitude mask, a refractivemask comprising refractive elements, or a diffractive mask comprisingdiffractive elements (e.g. a grating). In the example shown in FIG. 3A,LED projector 301 includes an amplitude mask 335. Amplitude maskembodiments transmit only a portion of the light emitted from LED source130 to generate a spatial intensity distribution on an image plane thatmay then be projected onto a scene to be illuminated based on thatspatial intensity distribution. For such embodiments, the focal distance(FD) between amplitude mask 335 and collector lens 341 is an importantparameter impacting MTF of projector 301. In some exemplary embodimentstherefore, amplitude mask 335 is in close proximity (e.g., directcontact) with collector lens 341. For example, amplitude mask 335 may beprinted, machined, or molded directly onto a surface of collector lens341 proximal to LED source 130.

Amplitude mask 335 may have any suitable pattern, such as, but notlimited to, a pseudo random feature pattern. The feature pattern in someembodiments has a 1:1 correspondence with a number of illuminationpoints to be projected (e.g., 1:1 mask opening:reimaged illuminationpoint). For example, amplitude mask 335 may be a dark field mask havinglow amplitude transmittance perforated with tens of thousands of holeshaving high amplitude transmittance. Such a mask may howeversignificantly reduce net light flux projected to an illuminated scene.Hence, in some embodiments offering greater efficiency, amplitude mask335 has a low amplitude transmittance feature count that is far belowthe projected illumination point count. For example, amplitude mask 335may comprise less than 50,000 low-transmittance features, advantageouslyless than 10,000 low-transmittance features, and more advantageouslyless than 1,000 low-transmittance features. As the low-transmittancefeature count decreases, the net transmittance is increased such thatillumination efficiency of amplitude mask 335 is improved. In someembodiments, amplitude mask 335 has between 100 and 1,000low-transmittance features, which may, for example, shape high-intensityillumination points to be other than what would occur if no amplitudemask was present and flood illumination from LED source 130 was merelyprojected onto a scene. For embodiments where amplitude mask 335 hasfewer features than is to be projected upon a scene, one or more ofcollector lens 341 and projector lens 342 are to further replicate abase pattern defined by features of amplitude mask 335.

In some embodiments, an LED pattern projector employs a refractive mask.Such a mask may be employed in absence of an amplitude mask, or incombination with an amplitude mask. A refractive mask may also generatea spatial intensity distribution onto an image plane that may then beprojected onto a scene. For such embodiments, the spatial intensitydistribution may be generated without blocking any portion of theemission from LED source 130 such that illumination efficiency may behigh. In further reference to FIG. 1, for some refractive maskembodiments, pattern mask 135 may be eliminated, or its functionessentially integrated into compound lens 340. In FIG. 3B for example,an LED pattern projector 302 is illustrated, which may again be employedas LED pattern projector 125 (FIG. 1). As shown in FIG. 3B, collector341 is a micro-lens array (MLA), comprising an array of lenslets 351.Each lenslet 351 may have any suitable shape with the illustratedexample being plano-convex lenslets having convex surface curvatureproximal to LED source 130. Each lenslet 351 will therefore collectlight from LED source 130, which is to be reimaged as a base patternonto an image plane beyond the planar side of lenslets 351. Thecumulative pattern generated by the MLA may then be reimaged byprojector lens 342. With the MLA providing patterned light collection,projector lens 342 may not require more than a single projection lens(e.g., a single plano-convex lens is depicted in FIG. 3B). The focaldistance (FD) between the MLA and the LED source is an importantparameter impacting MTF of projector 302. In some exemplary embodimentstherefore, the MLA is in close proximity (e.g., direct contact) with areference surface of LED source 130.

A collector MLA may include any number of lenslets 351. In someembodiments, the MLA includes no more than nine lenslets 351, eachreplicating a base illumination pattern. In some advantageousembodiments, the MLA includes at least twenty lenslets 351. In some moreadvantageous embodiments, the MLA includes at least one hundred lenslets351. With a larger number of lenslets, an illumination pattern may bereplicated a greater number of times permitting thousands ofillumination points to be generated from a simpler base illuminationpattern. For some embodiments, lenslets 351 are all substantiallyidentical within the array. In other embodiments, the size (e.g.,diameter) or refractive index of the individual microlenses is variedwithin the MLA, for example to affect the spatial intensity distributionthe MLA pattern to be projected. Focal lengths and/or lens shape mayalso be modulated within the MLA, for example to modulate the efficiencyof collection as needed to achieve a desired intensity distribution onan image plane of the MLA that can then be projected into a suitablepattern over a scene over some predetermined projector FOV.

In some further embodiments, an LED pattern projector employs arefractive mask and an amplitude mask. The amplitude mask may, forexample, be located between a MLA collector and an LED light source, forexample to improve spatial intensity contrast of a pattern generated onan image plane of the MLA collector. In FIG. 3C for example, a LEDpattern projector 303 is illustrated, which may again be employed as LEDpattern projector 125 (FIG. 1). As shown in FIG. 3C, collector 341comprises an array of lenslets 351 and amplitude mask 335 is betweenlenslets 351 and LED source 130. In this example, amplitude mask 335 maybe a bright field mask with relatively large transmissive feature sizehaving a lower count (e.g., 100-400 dots) and/or feature density (e.g.,100-400 dots/mm²) than what is to be projected onto a scene. The fixedbase pattern defined by amplitude mask 335 may be associated with anintensity distribution that is then replicated by each lenslet 351. Theimage planes of lenslets 351 are then reimaged onto a far-field scene byprojector lens 342.

FIG. 4A is a plan view of a MLA collector 401 comprising a sphericalarray of plano-convex lenslets 351, in accordance with some embodiments.MLA collector 401 may be employed as collector lens 341 in LED projector301, for example. As shown, MLA collector 401 is a monolithic array,which may have been manufactured according to any techniques known to besuitable for the purpose. MLA collector 401 may have any materialcomposition known to be suitable for a MLA, as embodiments herein arenot limited in this respect. In some exemplary embodiments, MLAcollector 401 comprises an acrylic, or a siloxane (e.g.,poly(dimethylsiloxane). In this example, many hundreds of lenslets areillustrated, however more or fewer may be employed, for example as afunction of the resolution of each lenslet.

FIG. 4B is a cross-sectional view of MLA collector 401B through the B-B′plane further illustrated in FIG. 4A, in accordance with some exemplaryembodiments. MLA collector 401B has spherical symmetry about a centralcollector axis 421. MLA collector 401B has a planar arrayed convexlenslet surface 420 and a substantially planar surface 410. In someexemplary embodiments, arrayed convex surface 420 is to be proximal to aLED source (not depicted), while planar surface 410 is to be distal fromthe LED surface (and proximal to a projector lens). Arrayed surface 420is depicted as substantially equidistant to planar surface 410 over adiameter of MLA collector 401A, however arrayed surface 420 may have anybest form for the incoming illumination, so as to minimize sphericalaberration. For example, an arrayed surface may have a compound convexshape over a diameter of the MLA collector lens in addition to theconvex shape over a diameter of each lenslet (i.e., a fly's eye compoundcollector lens architecture). An MLA collector may also haveconcave-convex architecture. For example, as further illustrated in FIG.4C. MLA collector 401C has a convex lenslets 425 array over a convexsurface proximal to a LED source (not depicted), and a smooth concavesurface 428 distal from the LED surface (and proximal to a projectorlens).

In some further embodiments, a refractive collector mask and a projectorlens are implemented with a single optical element (e.g., a moldedelement). For example, a MLA collector (e.g., comprising convexlenslets) may be molded into a convex or bi-convex lens form tointegrate the collector with the projector. FIG. 4D, for example, is across-sectional view (through the B-B′ plane further illustrated in FIG.4A) of a pattern projection lens 401C form including both a MLAcollector and a convex projection lens surface, in accordance with somealternative bi-convex embodiments. As shown in FIG. 4D, the MLAcollector comprises a convex array surface 415 that has long-rangeconvex curvature over a diameter of lens 401C in addition to ashort-range convex curvature over a diameter of each lenslet. For theillustrated embodiments, lens 401C depicts a fly's eye architecture.Lens 401C may further comprise a second convex surface 430, for examplehaving a curvature suitable for projecting the micropattern replicatedby the fly's eye collector lens surface. Convex array surface 415 mayagain be proximal to a LED source (not depicted), while convex surface430 is distal from the LED surface.

In some alternative embodiments, a LED pattern projector employs adiffractive optical element (DOE) to generate a spatial intensitydistribution of illumination from a LED source that is suitable forprojection upon a scene. The DOE may be employed alone, or incombination with one or more of an amplitude mask and a refractive mask.A DOE may include any suitable phase elements that may produce anydesired intensity distribution through interference and/or diffraction.Although DOEs are most often employed with collimated, coherentillumination, for example of the type most typical of a laser source,broadband DOEs have more recently also been designed for wider bandwidthsources, such as LED sources. For example, DOEs of the type employed insome LED-based optical transmitters are able to shape diffractionpatterns into polygons within the RGB band. Such polygons may then bereimaged onto a far-field scene, for example substantially as describedelsewhere herein.

For a DOE, phase shifts may be controlled through the use of step-shapedphase metastructures distributed sequentially over a lens. The phasemetastructures may, for example, have a surface roughness in thenanometer range, and the feature height of the phase steps indiffractive elements may be below the micrometer scale. DOEs maytherefore be considered “flat” optical elements because they can be muchthinner than conventional optical elements. For example, flat lenseshaving thicknesses of only tens or hundreds of nanometers (nm) have beenrecently developed. A DOE may include any metasurface that comprises aplurality of surface structures spatially arrayed over a substrate, suchas, but not limited to, polished quartz, or another material havingsimilar flatness. The nanostructures may also be referred to asnanoantennas because they are each capable of functioning as a resonantoptical antenna, which allows the metasurface to manipulate opticalwave-fronts (e.g., inducing a phase delay, which may be precisely tunedover a footprint of the array). A given nanostructure array may have adifferent focal length for different wavelengths. Hence, in someembodiments suitable for LED pattern projection, a LED pattern projectorincludes a plurality of flat lenses, each tuned for a different centersource wavelength.

In some embodiments, a LED pattern projector employs a projectorcomprising a MLA to reimage and replicate an illumination patterncollected from a LED source. FIG. 5A is a plan view of a lenslet arraythat may be employed in an LED pattern projector, in accordance withsome embodiments. In this example, many hundreds of lenslets areillustrated, however more or fewer may be employed, for example as afunction of the resolution of each lenslet. MLA projector 501 includes aspherical array of convex lenslets 551, in accordance with someembodiments. MLA projector 501 may be employed as projector lens 342 inLED projector 301, for example. MLA projector 501 may be monolithic andcomprise any suitable material(s) manufactured according to anytechniques known to be suitable for the purpose. In some exemplaryembodiments, MLA projector 501 comprises an acrylic, or a siloxane(e.g., poly(dimethylsiloxane). In this example, many hundreds oflenslets are illustrated, however more or fewer may be employed, forexample as a function of the resolution of each lenslet.

MLA projector 501 may include any number of lenslets 551. In someembodiments, MLA projector 501 includes no more than nine lenslets 551.In some advantageous embodiments, MLA projector 501 includes at leasttwenty lenslets 551. In some more advantageous embodiments, MLAprojector 501 includes at least one hundred lenslets 551. For someembodiments, lenslets 551 are all substantially identical within thearray. In other embodiments, the size (e.g., diameter) or refractiveindex of the individual microlenses may be varied within the MLA, forexample to affect the spatial intensity distribution the MLA pattern tobe projected. Focal lengths and/or lens shape may also be modulatedwithin the MLA, for example to modulate the efficiency of collection asneed to achieve a desired illumination intensity distribution over ascene within some predetermined FOV.

FIG. 5B is a cross-sectional view of MLA projector 501A through the B-B′plane further illustrated in FIG. 5A. MLA projector 501A is a firstexample of MLA projector 501, and has spherical symmetry about a centralprojector axis 521. As shown in FIG. 5B, MLA projector 501B has anarrayed convex surface 520 and a substantially planar surface 510, inaccordance with some exemplary embodiments. For projection, arrayedconvex surface 520 is to be distal from a LED source (not depicted),while surface 510 is proximal to the LED surface. Arrayed surface 520 isdepicted as substantially equidistant from planar surface 510 over thediameter of MLA projector 501, however arrayed surface 510 may have anybest form for the incoming illumination, for example so as to minimizespherical aberration. The arrayed surface may, for example, have aconvex shape over a diameter of a MLA projector, as is furtherillustrated in FIG. 5C for MLA projector 501B. For such embodiments, aconvex array surface 515 has long-range convex curvature over a diameterof MLA projector 501B, in addition to a short-range convex curvatureover a diameter of each lenslet of convex array surface 515. Hence, MLAprojector 501B has a fly's eye architecture. Convex array surface 515 isagain to be distal from a LED source with (planar) surface 510 proximalto the LED source. The arrayed surface may also have a concave-convexshape over a diameter of a MLA projector, as is further illustrated inFIG. 5D for MLA projector 501C. For such embodiments, convex arraysurface 515 has long-range convex curvature over a diameter of MLAprojector 501C. In this embodiment however, surface 510 (proximal to theLED source) is concave rather than planar.

In some embodiments, a MLA projector is integrated with one or more ofan amplitude mask, refractive mask, or diffractive mask. For some suchembodiments where mask features are printed, machined, or molded into a(collector) surface of the MLA, the focal distance between the mask andthe lenslet array can be advantageously fixed to a desired predeterminedvalue. FIGS. 6A, 6B, 6C, and 6D are cross-sectional views of maskedlenslet arrays that may be employed in LED pattern projectors, inaccordance with some embodiments.

In the example shown in FIG. 6A, a mask material 635 is in contact witha projector lens material 642. Lens material 642, may for example,comprise an acrylic, or a siloxane (e.g., poly(dimethylsiloxane). Maskmaterial 635 has a different composition than lens material 642. Forsome exemplary amplitude mask embodiments where lens material 642 is afirst material transmissive over a band emitted by an LED source, maskmaterial 635 may be one or more second materials that are significantlyless transmissive (e.g., opaque to the band emitted by an LED source)than lens material 642. For some exemplary refractive or diffractivemask embodiments where lens material 642 is a first material having afirst refractive index over a band emitted by an LED source, maskmaterial 635 may be one or more second materials that are alsotransmissive over the band emitted by an LED source. The secondmaterial(s) however have a second refractive index over the emissionband that provides a suitable index contrast with lens material 642.Mask material 635 may, for example, be laminated, printed, or otherwisephysically applied to surface 510 (proximal to an LED source). Maskmaterial 635 may contain a pigment delivered in a carrier (e.g., anink), for example. The ink may be directly printed onto lens surface 510by any suitable process to define a predetermined mask feature pattern(e.g., 20×20 dot/mm²). In other embodiments, a continuous mask materialmay be deposited onto lens surface 510 as a thin film, a spin-on, or adry film laminate. The mask material may then be photolithographicallypatterned, or chemically etched according to a photolithographicallydefined sacrificial mask, to expose a portion of lens surface 510 andthereby define the mask feature pattern.

In the example shown in FIG. 6A, projector lens material 642 is moldedto have a convex lenslet array surface 515, for example substantially asdescribed above. Projector lens material 642 is further molded to have asidewall 650 of any thickness T_(FD) that defines a suitable workingdistance between the lenslet array surface 515 and mask 635. The use ofdashed line in FIG. 6A is to emphasize sidewall 650 may define anythickness T_(FD).

In the example shown in FIG. 6B, a mask material 636 is embedded withinprojector lens material 642. Mask material 636 again has a differentcomposition that projector lens material 642. For some exemplaryamplitude mask embodiments where lens material 642 is a first materialthat has high transmittance over a band emitted by an LED source, maskmaterial 636 may be one or more second materials that have significantlylower transmittance (e.g., opaque to the band emitted by an LED source)than lens material 642. For some exemplary refractive or diffractivemask embodiments, mask material 635 may again be one or more secondmaterials that are also transmissive over the band emitted by an LEDsource, but have a second refractive index that provides a suitableindex contrast with lens material 642. Mask material 636 may be writteninto surface 510, for example. Mask material 636 may be a conversionproduct that reduces amplitude transmittance within a portion of lensmaterial 642. In some embodiments, lens material 642 may be burned (e.g.with a suitable laser) to define a predetermined feature pattern (e.g.,20×20 dot/mm²) embedded within lens material 642.

In the example shown in FIG. 6C, refractive and/or diffractive maskfeatures 637 are machined into lens material 642. For such embodiments,lens material 642 is to both generate a spatial intensity distribution(e.g., with refractive and/or diffractive mask features 637), andproject that spatial intensity distribution onto an illuminated scene(e.g., with convex array surface 515). In the example shown in FIG. 6D,refractive and/or diffractive mask features 638 are molded into lensmaterial 642. A collector lens surface and a projector lens surfacehaving any of the features described individually elsewhere herein maybe machined into and/or molded from a homogenous material, for example.

Notably, a pattern projector in accordance with embodiments herein neednot have spherical symmetry and may have a variety of customizable formfactors. FIGS. 7A and 7B are isometric views of a pattern projector 701that includes a pattern mask and a lenslet array, in accordance withsome embodiments. As shown in FIGS. 7A and 7B, pattern projector 701includes mask 635 at a first (collector) end. Mask 635 occupies only aportion of a collector area having first lateral dimensions C_(x) andC_(y). Pattern projector 701 is in the form of a trapezoidal prism withlateral dimensions C_(x) and C_(y) being smaller than second lateraldimensions P_(x) and P_(y) associated with a second (projector) end. Thecollector and projector ends are separated by a volume further definedby sidewall 650 that has a length defining thickness T_(FD). In theillustrated example, T_(FD) is significantly longer than C_(x), C_(y),P_(x), or P_(y). Although T_(FD) may vary, for the radius of curvatureand refractive index of material 642, T_(FD) is between 3 and 7 timesC_(x) (or C_(y)). At the projector end, is convex microlenslet array(MLA) surface 515 comprising a square (e.g., 3×3) array of projectionlenslets. The nine lenslets are arranged with the substantially squareprojector end defined by lateral dimensions P_(x) and P_(y). As shown inFIG. 7B, portions of lenslet array surface 515 extend slightly beyondflat surfaces of the trapezoidal prism.

FIG. 7C is a schematic of LED pattern projection with a patternprojector 701, in accordance with some embodiments. In the exampleshown, the intensity of light emitted from LED source 130 is spatiallymodulated by mask material 635. The resulting spatial intensitydistribution is a base micropattern that is reimaged by patternprojector 701 to illuminate a scene within field of illumination 111. Inthe example shown, a fly's eye projector lens architecture replicatesthe base micropattern over multiple (e.g., nine) projected patternregions 710, each region comprising illumination points 715 associatedwith the micropattern. Within each of regions 710 is a patternprojection from one lenslet of MLA projector 501. Hence, mask material635 with a given spatial intensity distribution (e.g., 20×20illumination points/mm²) may generate a micropattern on an image planeof pattern projector 701, and each lenslet of pattern projector 701(e.g., a 3×3 lens array) may reimage, or project, the micropattern overa depth to generate a composite projection filling projector FOV 111.Although a 3×3 lens array is for the sake of clarity, larger arrays(e.g., 10×10, 100×100, etc.) may be similarly employed.

FIG. 8 is device platform 800 including camera module hardware (CM) 830and a pattern projector 125, in accordance with some embodiments. In theillustrated embodiment, CM 830 further includes EEPROM 856, optionallens motor(s) 857, and image sensors 115A, 115B.

Image sensor 115A may have any of the properties described elsewhereherein. CM 830 may have a number of control registers (e.g., 16-bit)addressable for example, through a camera control bus with an 8-bitaddress. Control registers of CM 830 may be programmed for examplethrough an I²C serial interface managed by camera control bus controller825 (e.g., an I²C controller).

CM 830 is to output image data 860. This data may include a descriptionof the CM control parameters (e.g., exposure parameters such as exposuretime, analog gain, digital gain, etc.) that were in effect duringcollection of the raw image data. Image data 860 is passed to a sensorreceiver 854 that supports the streaming protocol employed by CM 830,such as a MIPI or other input protocol. Sensor receiver 854 is furtherto output raw image data 872 to one or more image signal processor (ISP)851.

ISP 851 may receive and analyze the raw image data 872 during thehorizontal and/or vertical blanking periods associated with CM 830.During raw image data processing, ISP 851 may perform one or more ofcomputation of depth information, noise reduction, pixel linearization,and shading compensation, for example. ISP 851 may also performresolution reduction, Bayer demosaic, and/or vignette elimination, forexample. ISP 851 may also calculate image statistics information. Imagestatistics may include luminance/chrominance values and averages,luminance/chrominance high frequency and texture content, motion contentfrom frame to frame, any other color content values, picture statisticaldata regarding deblocking control (for example, information controllingdeblocking/non-deblocking), filter response grid, and RGB histograms,etc. ISP 851 may be compatible with video codecs, such as H.264/AdvancedVideo Coding (AVC) or High Efficiency Video Coding (HEVC), JPEG. etc.,which may be utilized to post-process YUV data and generatereconstructed image data and calculated 3A statistics 877. Reconstructedimage data and calculated 3A statistics 877 are stored in memory 870(e.g., a double data rate (DDR), or other suitable memory).Reconstructed image data 885 may then be read out to one or more of astorage, display pipeline or transmission pipeline 890, to storedisplay, or transmit a representation of collected frames.

3A statistics 875 may be accessed from memory 810 by applicationsprocessor 850 for further analysis, for example during a 3A control loopiteration. In the exemplary embodiment, applications processor 850instantiates an operating system including a user space and a kernelspace. Applications processor 850 may have many functions within adevice platform beyond camera control. Applications processor 850 may bea large vector processor with access to main memory 810. Applicationsprocessor 850 is to execute camera control algorithm(s) 855, based onfor example 3A input 877 received through CM abstraction layer 808. CMabstraction layer 808 may be any hardware abstraction layer configuredfor the particular operating system instantiated. CM abstraction layer808 may for example handle compatibility between third-party 3A controlalgorithms and CM 830, and/or ISP 851.

Execution of CCA 855 may further entail accessing at least one of anautomatic exposure or automatic white balance library stored in mainmemory 810 to generate CM control parameter values. In one exemplary AECembodiment, execution of CCA 855 entails performing an exposurecalculation that generates target total exposures and correspondingframe numbers. The target total exposures are included in 3A output 856passed to CM abstraction layer 808. CM abstraction layer 808 passesvalues in 3A output 856 associated with CM 830 as CM control parametervalues 866 to CM driver 815. CM abstraction layer 808 passes values in3A output 856 associated with ISP 851 as ISP control parameter values867 to ISP driver 816.

CM driver 815 passes CM control parameter values 866 to CM controller850. ISP driver 816 likewise passes ISP control parameter values 867 toCM controller 850 where the values are queued and sequentiallydispatched as CM parameter values 866 to CM bus controller 825. CM buscontroller 825 writes CM values 866 to a CM register in synchronizationwith actions of CM 830 associated with exposing a next frame, andconsecutive frames thereafter. CM controller 852 is further to queue ISPvalues 867 and sequentially dispatches them to ISP 851.

In an exemplary embodiment, CM controller 850 is further to communicatesync parameters 899 to pattern projector 125. Projector 125 includes anLED source, a mask to spatially modulate intensity of light emitted bythe LED, and one or more projector lenses, for example as describedelsewhere herein. Sync parameters 899 may be based on CM parametersvalues 866. For example, sync parameters 899 may include an indicationof integration time that will be used by sensor array 115A for anupcoming frame collection. Sync parameters 899 may specify a LED emitterduty cycle, or otherwise specify an illumination time that is to beemployed when CM 830 subsequently triggers projector 125. Syncparameters 899 may further specify a LED emitter peak power level thatis to be employed when CM 830 subsequently triggers projector 125.Although illustrated as a component external to CM 830, projector 125may instead be a component of CM 830. For such embodiments, CM values866 may specify a projector LED duty cycle or otherwise specify anillumination time when projector 125 is subsequently triggered.

FIG. 9 is an illustrative diagram of an exemplary system 900, inaccordance with embodiments. System 900 may be a mobile device althoughsystem 900 is not limited to this context. For example, system 900 maybe incorporated into a laptop computer, ultra-laptop computer, tablet,touch pad, portable computer, handheld computer, palmtop computer,cellular telephone, smart device (e.g., smart phone, smart tablet ormobile television), mobile internet device (MID), messaging device, datacommunication device, and so forth. System 900 may also be aninfrastructure device. For example, system 900 may be incorporated intoa large format television, set-top box, desktop computer, or other homeor commercial network device.

System 900 includes a device platform 902 that may implement all or asubset of the various camera and illumination projection methods as wellas any of the camera control platforms described above. CPU 950 mayinclude logic circuitry to generate a frame-based series of controlparameters for controlling CM 830 and projector 125. In someembodiments, one or more computer readable media may store instructions,which when executed by CPU 950, cause the processor to generate aframe-based series of control parameters for controlling CM 830 andprojector 125. One or more image frame exposed by CM 830 using lightprojection determined by CPU 950 may then be stored in memory 912.

In embodiments, device platform 902 is coupled to a human interfacedevice (HID) 920. Platform 902 may collect raw image data with CM 830,which is processed based on depth information (e.g., with depthprocessor 970), and output to HID 920. A navigation controller 960including one or more navigation features may be used to interact with,for example, device platform 902 and/or HID 920. In embodiments, HID 920may include any television type monitor or display coupled to platform902 via radio 918 and/or network 965. HID 920 may include, for example,a computer display screen, touch screen display, video monitor,television-like device, and/or a television.

Under the control of one or more software applications 913, deviceplatform 902 may display user interface 922 on HID 920. Movements of thenavigation features of controller 950 may be replicated on a display(e.g., HID 920) by movements of a pointer, cursor, focus ring, or othervisual indicators displayed on the display. For example, under thecontrol of software applications 913, the navigation features located onnavigation controller 960 may be mapped to virtual navigation featuresdisplayed on user interface 922.

Device platform 902 may include any combination of projector 125, CM830, chipset 905, processor 950, controller 960, memory 912, storage911, applications 913, and radio 918 known in the art. Chipset 905 mayprovide intercommunication among projector 125, CM 830, processor 950,controller 850, memory 912, storage 911, applications 913 and radio 918.

Processor 950 may be implemented as one or more Complex Instruction SetComputer (CISC) or Reduced Instruction Set Computer (RISC) processors;x86 instruction set compatible processors, multi-core, or any othermicroprocessor or central processing unit (CPU). Memory 912 may beimplemented as a volatile memory device such as, but not limited to, aRandom Access Memory (RAM), Dynamic Random Access Memory (DRAM), orStatic RAM (SRAM). Storage 911 may be implemented as a non-volatilestorage device such as, but not limited to, a magnetic disk drive,optical disk drive, tape drive, an internal storage device, an attachedstorage device, flash memory, battery backed-up SDRAM (synchronousDRAM), and/or a network accessible storage device. Radio 918 may includeone or more radios capable of transmitting and receiving signals usingvarious suitable wireless communications techniques. Such techniques mayinvolve communications across one or more wireless networks. Examplewireless networks include (but are not limited to) wireless local areanetworks (WLANs), wireless personal area networks (WPANs), wirelessmetropolitan area network (WMANs), cellular networks, and satellitenetworks. In communicating across such networks, radio 918 may operatein accordance with one or more applicable wireless standards versions.

In embodiments, system 900 may be implemented as a wireless system, awired system, or a combination of both. When implemented as a wirelesssystem, system 900 may include components and interfaces suitable forcommunicating over a wireless shared media, such as one or moreantennas, transmitters, receivers, transceivers, amplifiers, filters,control logic, and so forth. An example of wireless shared media mayinclude portions of a wireless spectrum, such as the RF spectrum and soforth. When implemented as a wired system, system 900 may includecomponents and interfaces suitable for communicating over wiredcommunications media, such as input/output (I/O) adapters, physicalconnectors to connect the I/O adapter with a corresponding wiredcommunications medium, a network interface card (NIC), disc controller,video controller, audio controller, and the like. Examples of wiredcommunications media may include a wire, cable, metal leads, printedcircuit board (PCB), backplane, switch fabric, semiconductor material,twisted-pair wire, co-axial cable, fiber optics, and so forth.

Pattern projection and/or camera architectures described herein may beimplemented in various hardware architectures, cell designs, or “IPcores.”

As described above, system 900 may be embodied in varying physicalstyles or form factors. FIG. 10A illustrates embodiments of a mobilehandset device 1000 in which system 900 may be embodied. In embodiments,for example, device 1000 may be implemented as a mobile computing devicehaving wireless capabilities. A mobile computing device may refer to anydevice having a processing system and a mobile power source or supply,such as one or more batteries, for example. Examples of a mobilecomputing device may include a personal computer (PC), laptop computer,ultra-laptop computer, tablet, touch pad, portable computer, handheldcomputer, palmtop computer, personal digital assistant (PDA), cellulartelephone, combination cellular telephone/PDA, television, smart device(e.g., smartphone, tablet or smart television), mobile internet device(MID), messaging device, data communication device, and so forth.Examples of a mobile computing device also may include computers and/ormedia capture/transmission devices configured to be worn by a person,such as a wrist computer, finger computer, ring computer, eyeglasscomputer, belt-clip computer, arm-band computer, shoe computers,clothing computers, and other wearable computers. In variousembodiments, for example, a mobile computing device may be implementedas a smart phone capable of executing computer applications, as well asvoice communications and/or data communications. Although someembodiments may be described with a mobile computing device implementedas a smart phone by way of example, it may be appreciated that otherembodiments may be implemented using other wireless mobile computingdevices as well. The embodiments are not limited in this context.

As shown in FIG. 10A, mobile handset device 1000 may include a housingwith a front 1001 and back 1002. Device 1000 includes a display 1004, aninput/output (I/O) device 1006, and an integrated antenna 1008. Device1000 also may include navigation features 1012. Display 1004 may includeany suitable display unit for displaying information appropriate for amobile computing device. I/O device 1006 may include any suitable I/Odevice for entering information into a mobile computing device. Examplesfor I/O device 1006 may include an alphanumeric keyboard, a numerickeypad, a touch pad, input keys, buttons, switches, microphones,speakers, voice recognition device and software, and so forth.Information also may be entered into device 1000 by way of microphone(not shown), or may be digitized by a voice recognition device.Embodiments are not limited in this context. Integrated into at leastthe back 1002 is camera 1005 (e.g., including one or more lenses,apertures, and image sensors). Also visible in back 1002 is lightpattern projector 125, for example as described elsewhere herein.

FIG. 10B is a diagram of an exemplary quadcopter platform 1050 includingone or more camera 1005 and light pattern projector 125, in accordancewith some embodiments. Each camera 1005 may include one or more lenses,apertures, and image sensors. Light pattern projector 125 may have anyof the attributes described elsewhere herein, and may be synchronizedwith camera 1005 in one or more of the manners described elsewhereherein. Quadcopter platform 1050 includes two pairs of fixed pitchedpropellers; a first pair providing lift when rotating clockwise (CW) anda second pair providing lift when rotating counterclockwise (CCW).Quadcopter platform 1050 includes one or more computer processors,electronic accelerometers, and a global positioning system (GPS).Quadcopter platform 1050 may be configured for autonomous aerialphotography and/or surveillance. Computer processors may executesoftware, such as the PX4 autopilot system, that allows a user to defineway-points to which the quadcopter platform 1050 will autonomously flyand perform a task. One such task may be aerial photography with camera1005 operating with a rolling shutter synchronized with rollingillumination from light projection array 100, for example as describedelsewhere herein.

Embodiments described herein may be implemented using hardware elements,software elements, or a combination of both. Examples of hardwareelements or modules include: processors, microprocessors, circuitry,circuit elements (e.g., transistors, resistors, capacitors, inductors,and so forth), integrated circuits, application specific integratedcircuits (ASIC), programmable logic devices (PLD), digital signalprocessors (DSP), field programmable gate array (FPGA), logic gates,registers, semiconductor device, chips, microchips, chip sets, and soforth. Examples of software elements or modules include: applications,computer programs, application programs, system programs, machineprograms, operating system software, middleware, firmware, routines,subroutines, functions, methods, procedures, software interfaces,application programming interfaces (API), instruction sets, computingcode, computer code, code segments, computer code segments, data words,values, symbols, or any combination thereof. Determining whether anembodiment is implemented using hardware elements and/or softwareelements may vary in accordance with any number of factors consideredfor the choice of design, such as, but not limited to: desiredcomputational rate, power levels, heat tolerances, processing cyclebudget, input data rates, output data rates, memory resources, data busspeeds and other design or performance constraints.

One or more aspects of at least one embodiment may be implemented byrepresentative instructions stored on a machine-readable storage medium.Such instructions may reside, completely or at least partially, within amain memory and/or within a processor during execution thereof by themachine, the main memory and the processor portions storing theinstructions then also constituting a machine-readable storage media.Programmable logic circuitry may have registers, state machines, etc.configured by the processor implementing the computer readable media.Such logic circuitry, as programmed, may then be understood to have beenphysically transformed into a system falling within the scope of theembodiments described herein. Instructions representing various logicwithin the processor, which when read by a machine may also cause themachine to fabricate logic adhering to the architectures describedherein and/or to perform the techniques described herein. Suchrepresentations, known as cell designs, or IP cores, may be stored on atangible, machine-readable medium and supplied to various customers ormanufacturing facilities to load into the fabrication machines thatactually make the logic or processor.

As used in any implementation described herein, the term “module” refersto any combination of software, firmware and/or hardware configured toprovide the functionality described herein. The software may be embodiedas a software package, code and/or instruction set or instructions, and“hardware”, as used in any implementation described herein, may include,for example, singly or in any combination, hardwired circuitry,programmable circuitry, state machine circuitry, and/or firmware thatstores instructions executed by programmable circuitry. The modules may,collectively or individually, be embodied as circuitry that forms partof a larger system, for example, an integrated circuit (IC), systemon-chip (SoC), and so forth.

While certain features set forth herein have been described withreference to various implementations, this description is not intendedto be construed in a limiting sense. Hence, various modifications of theimplementations described herein, as well as other implementations,which are apparent to persons skilled in the art to which the presentdisclosure pertains are deemed to lie within the spirit and scope of thepresent disclosure.

Further examples of specific embodiments are now provided below.

In first examples, a camera platform comprises an image sensor array tocollect light from portions of a scene within a field of view of theimage sensor array. The platform comprises a light projector to cast alight pattern upon portions of the scene. The light projector furthercomprises a light emitting diode (LED) source, a mask to spatiallymodulate an intensity of emissions from the LED, and a projector lens toreimage the spatially modulated emission onto the portions of the scene.

In second examples, for any of the first examples, the LED sourcecomprises a first emitter having a half-emission cone angle of at least45°, and an emission spectrum of at least 4 nm. A first sensor pixelline is to integrate photocharge for a first portion of the scene over afirst time increment. A second sensor pixel line is to integratephotocharge for a second portion of the scene over a second timeincrement, and the light projector is to illuminate the first portionand second portions of the scene with illumination from the first lightemitter during the first and second time increments.

In third examples, for any of the first through second examples, themask is an amplitude mask comprising a mask pattern of high and lowamplitude transmittance regions.

In fourth examples, for any of the first through third examples, themask is between the LED source and the projector lens, and wherein theprojector lens comprises a microlens array (MLA).

In fifth examples, for any of the fourth examples the MLA comprises aplurality of lenslets, each having a convex surface distal from the LEDsource, and the mask is in contact with a surface of the projector lensproximal to the LED source.

In sixth examples, for any of the fourth through fifth examples the maskpattern comprises at least 400 features and wherein the MLA comprises atleast 9 lenslets.

In seventh examples, for any of the fourth through sixth examples, themask is in contact with a substantially planar lens surface, wherein theMLA comprise a first material, and wherein the low transmittance regionscomprise a second material of a different composition than the firstmaterial.

In eighth examples, for any of the fourth through seventh examples, theprojector lens has a fly's eye architecture in which the MLA has convexsurface curvature over a diameter of the projector lens.

In ninth examples, for any of the first examples the mask is arefractive mask comprising a microlens array (MLA), the MLA comprising aplurality of lenslets, each having a convex surface proximal to the LEDsource.

In tenth examples, for any of the ninth examples the mask and theprojector lens comprise a monolithic optical element of substantiallyhomogeneous composition.

In eleventh examples, a pattern projector to cast a light pattern uponportions of the scene comprises an amplitude mask comprising a maskpattern of high and low transmittance regions to spatially modulate anintensity of an illumination source, and a projector lens, wherein theprojector lens comprises a microlens array (MLA) including a firstlenslet to reimage the spatially modulated emission onto a first portionof a scene, and a second lenslet to reimage the spatially modulatedemission onto a first portion of a scene.

In twelfth examples, for any of the eleventh examples, the mask is incontact with a first projector surface, and wherein the first and secondlenslets each have a convex surface distal from the mask.

In thirteenth examples, for any of the eleventh through twelfth examplesthe mask pattern comprises at least 400 features and wherein the MLAcomprises at least 9 lenslets.

In fourteenth examples, for any of the twelfth examples the projectorlens has a fly's eye architecture in which the MLA has convex surfacecurvature over a diameter of the projector lens.

In fifteenth examples, for any of the twelfth through fourteenthexamples the projector comprises a second MLA, the second MLA comprisinga plurality of lenslets, each having a convex surface opposite theconvex surface of the first MLA.

In sixteenth examples, for any of the fifteenth examples the first andsecond MLA comprise a monolithic optical element of substantiallyhomogeneous composition.

In seventeenth examples, a method of fabricating a pattern projectorcomprises molding a projector lens, the projector lens including amicrolens array (MLA) having a first lenslet and a second lenslet, eachhaving a convex surface, and applying a mask to a surface of theprojector lens opposite the convex surfaces of the lenslets, wherein themask comprises a pattern of high and low amplitude transmittanceregions.

In eighteenth examples, for any of the seventeenth examples applying themask further comprises at least one of: printing the low transmittanceregions with an ink, laminating a dry film onto the projector lens andpatterning the dry film into the low transmittance regions, or modifyingportions of the projector lens material into the low transmittanceregions through laser processing.

In nineteenth examples, for any of the seventeenth examples molding theprojector lens further comprises molding an optically transmissivematerial into a fly's eye projector lens in which the MLA has convexsurface curvature over a diameter of the projector lens.

In twentieth examples, for any of the seventeenth through eighteenthexamples, the method further comprises assembling the projector lenswith an LED light source.

It will be recognized that the embodiments is not limited to theembodiments so described, but can be practiced with modification andalteration without departing from the scope of the appended claims. Forexample, the above embodiments may include specific combination offeatures. However, the above embodiments are not limited in this regardand, in various implementations, the above embodiments may include theundertaking only a subset of such features, undertaking a differentorder of such features, undertaking a different combination of suchfeatures, and/or undertaking additional features than those featuresexplicitly listed. The scope of the embodiments should, therefore, bedetermined with reference to the appended claims, along with the fullscope of equivalents to which such claims are entitled.

What is claimed is:
 1. A camera platform comprising: an image sensorarray to collect light from portions of a scene within a field of viewof the image sensor array; and a light projector to cast a light patternupon portions of the scene, wherein the light projector furthercomprises: a light emitting diode (LED) source; a mask to spatiallymodulate an intensity of emission from the LED source; and a projectorlens to reimage the spatially modulated emission onto the portions ofthe scene, wherein the projector lens comprises a microlens array (MLA)including a first lenslet to reimage the spatially modulated emissiononto a first portion of the scene, and a second lenslet to reimage thespatially modulated emission onto a second portion of the scene.
 2. Thecamera platform of claim 1, wherein: the LED source comprises a firstemitter having a half-emission cone angle of at least 45°, and anemission spectrum of at least 4 nm; a first sensor pixel line is tointegrate photocharge for a first portion of the scene over a first timeincrement; a second sensor pixel line is to integrate photocharge for asecond portion of the scene over a second time increment; and the lightprojector is to illuminate the first portion and second portion of thescene with illumination from the first emitter during the first andsecond time increments.
 3. The camera platform of claim 1, wherein themask is an amplitude mask comprising a mask pattern of high and lowamplitude transmittance regions.
 4. The camera platform of claim 3,wherein the mask is between the LED source and the projector lens. 5.The camera platform of claim 1, wherein the lenslets each have a convexsurface distal from the LED source and wherein the mask is in contactwith a surface of the projector lens proximal to the LED source.
 6. Thecamera platform of claim 5, wherein the mask comprises at least 400features and wherein the MLA comprises at least 9 lenslets.
 7. Thecamera platform of claim 5, wherein the mask is in contact with asubstantially planar lens surface, wherein the MLA comprise a firstmaterial, and wherein the low transmittance regions comprise a secondmaterial of a different composition than the first material.
 8. Thecamera platform of claim 1, wherein the projector lens has a fly's eyearchitecture in which the MLA has convex surface curvature over adiameter of the projector lens.
 9. The camera platform of claim 1,wherein the mask and the projector lens comprise a monolithic opticalelement of substantially homogeneous composition.
 10. A patternprojector to cast a light pattern upon portions of a scene, wherein thepattern projector further comprises: an amplitude mask comprising a maskpattern of high and low transmittance regions to spatially modulate anintensity of an illumination source; and a projector lens, wherein theprojector lens comprises a microlens array (MLA) including a firstlenslet to reimage the spatially modulated emission onto a first portionof a scene, and a second lenslet to reimage the spatially modulatedemission onto a second portion of the scene.
 11. The pattern projectorof claim 10, wherein the mask is in contact with a first projectorsurface, and wherein the first and second lenslets each have a convexsurface distal from the mask.
 12. The pattern projector of claim 11,wherein the mask pattern comprises at least 400 features and wherein theMLA comprises at least 9 lenslets.
 13. The pattern projector of claim11, wherein the projector lens has a fly's eye architecture in which theMLA has convex surface curvature over a diameter of the projector lens.14. The pattern projector of claim 10, further comprising a second MLA,the second MLA comprising a plurality of lenslets, each having a convexsurface opposite the convex surface of the first MLA.
 15. The patternprojector of claim 14, wherein the first and second MLA comprise amonolithic optical element of substantially homogeneous composition. 16.A method of fabricating a pattern projector, the method comprising:molding a projector lens, the projector lens including a microlens array(MLA) having a first lenslet and a second lenslet, each having a convexsurface; and applying a mask to a surface of the projector lens oppositethe convex surfaces of the lenslets, wherein the mask comprises apattern of high and low amplitude transmittance regions.
 17. The methodof claim 16, wherein applying the mask further comprises at least oneof: printing the low transmittance regions with an ink, laminating a dryfilm onto the projector lens and patterning the dry film into the lowtransmittance regions, or modifying portions of the projector lensmaterial into the low transmittance regions through laser processing.18. The method of claim 16, wherein molding the projector lens furthercomprises molding an optically transmissive material into a fly's eyeprojector lens in which the MLA has convex surface curvature over adiameter of the projector lens.
 19. The method of claim 16, furthercomprising assembling the projector lens with an LED light source.